Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: gutierre@nsipo.arc.nasa.gov (Robert Gutierrez) Newsgroups: comp.dcom.telecom Subject: Re: More 800, 900 Curiosities Message-ID: <4415@accuvax.nwu.edu> Date: 26 Feb 90 07:12:57 GMT Sender: news@accuvax.nwu.edu Reply-To: Robert Gutierrez Organization: NASA ARC Lines: 42 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 129, Message 5 of 9 c186aj@cory.berkeley.edu (Steve Forrette) writes: > >You got timed out while the local MCI switch was polling the 2 VAX's > >they use for 800 number lookup. > >And then there was this one time when both VAX's died for 45 minutes.... > If it is true that just 2 VAXes (or the leased lines going to them) going > down can bring down the entire MCI 800 system, perhaps AT&T's promise of > 1 hour service restoration for downed 800 lines isn't all that half-baked... In another article, Rick Wessman correctly points out that these computers are CCI Power 6/32-FT's. These are fault-tolerant computers, and as such, they are less prone to 'go down'. But, as was proved in AT&T's fiasco, just because the computer has double back-ups, that doesn't mean the code loaded into them can't go bad. If I remember correctly, that was the problem in MCI's 45 minute 'outage'. MCI, almost one year ago, upgraded the DAP's ("Data Access Point") to do number-table updates every 15 minutes instead of every night, so that emergency rerouting could be offered to their customers. If a customer is having a local problem, and has a pre-defined emergency plan submitted, he or she can call MCI and give a password, and can have that emergency plan implemented within 15 minutes (the next update to the DAP's). The software to do this was apparently very tricky, since updates and lookups were being done almost the same time now. Also, the software upgrade was to do call-restriction down to the NPA-NXX level, as opposed to just the State level before that. Also, it was the beta test of calling-number delivery. As with the switches, the hardware may be excellent, but the software sometimes can have problems....especially if you have 1E+32 patches to it..... Robert Gutierrez NASA Science Internet Network Operations Moffett Feild, California. "You know, all of my patients had one thing in common...... ....They all hated the phone company." James Coburn, "The Presidents Analyst".